Seats, such as, for example, vehicle seats in trucks, are often times supported by an air bladder. In such an arrangement, the air bladder acts as a suspension system for the seat and the height of the seat may be determined by the amount of pressurized air in a bladder. Pressurized air may be introduced into the bladder to increase the height of the seat. Similarly, pressurized air may be removed from the bladder to decrease the height of the seat. The present invention is directed at providing a leveling valve that maintains a generally constant seat height in such a system when a clutch of the leveling valve is engaged. The present invention is directed at providing a leveling valve that allows the height of the seat to be adjusted when the clutch of the leveling valve is disengaged. Other preferred aspects of the present invention are set forth below.